Tethering device



FIG. 1 is a front perspective view of a tethering device, showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a bottom plan view thereof.

The broken line disclosure of a dog and chain in FIG. 1 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a tethering device, as shown and described. 